Detection of the±32↔±12Satellite Spectrum ofNa23inβ-Alumina via Double-Resonance Interferometry

A nuclear double-resonance interferometric technique is developed and applied to a spin-$\frac{3}{2}$ system. The $90°\left({\nu }_1\right)-360\mathrm{}°\left({\nu }_2\right)$ pulse scheme which is applied to ${}_{}{}^{23}{}_{}{}^{}\mathrm{Na}$ in $\beta$-alumina allows the indirect detection of the first-order quadrupolar-shifted spectrum (the $\frac{3}{2}\to \frac{1}{2}$ and $-\frac{1}{2}\to -\frac{3}{2}$ transitions) through observation of the phase of the ½ → -½ central line. The broad satellites of the ${}_{}{}^{23}{}_{}{}^{}\mathrm{Na}$ spectrum in single-crystal $\beta$-alumina thus mapped out have not been reported in numerous previous NMR studies of this material.